The Doppler shift formula gives the frequency fL at which a listener L hears the sound emitted by a source S at frequency fS: fL = fS(v+vL)/(v+vS), where v is the speed of sound in the medium, vL is the velocity of the listener, and vS is the velocity of source.

The nuclear potential that binds protons and neutrons in the nucleus of an atom is often approximated by a square well. imagine a proton conned in an innite square well of length 105 nm, a typical nuclear diameter. calculate the wavelength and energy associated with the photon that is emitted when the proton undergoes a transition from the rst excited state (n 2) to the ground state (n 1). in what region of the electromagnetic spectrum does this wavelength belong?